And then there were eight: astronomers no longer count Pluto as a planet

On Thursday 24 August in Prague, the 26th General Assembly of the International Astronomical Union (IAU) agreed on the first ever scientific definition of a planet. Objects in the Solar System will now be grouped into three categories. Firstly there are the eight planets, already well-known to astronomers even before the 20th century. Then there is the ever-growing number of dwarf planets, identified as the result of numerous observations, and lastly, there are the countless small bodies of our Solar System. The eight planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Pluto, named after the Roman god of the underworld, is now classified as a dwarf planet – like the trans-Neptunian object 2003 UB313 and the asteroid Ceres.

Send article link to:

Your e-mail address:

Your message:

CaptchaPlease enter code:

Any details you supply are not stored. You will receive no unsolicited e-mails as a result.